Timing device



1952 M. VAN VALKENBURGH E'AL 2,583,245

TIMING DEVICE Filed Aug. 8, 1949 2 SE-IEETS-Sl-IEET l gvwwwfow MERE/7'7"VAN MALKENBURGH LAWRENCE 1 LAV/ANA w, WW

' 1952 M. VAN VALKENBURGH ETAL' 2,5 3, 4

TIMING DEVICE 2 SHEETSSHEET 2 Filed Aug. 8, 1949 NEHRJTT VAN MALKENBURGHLAWRENCE JLAVJANA Patented Jan. 22, 1952 UNITED STATES PATENT OFFICETIMING DEVICE Application August 8, 1949, Serial No. 109,114

7 Claims.

Th inventionrclates to improvements in timin:v devices, and moreparticularly; to such devices known as interval timers. Interval timerswally comprise. clockwork mechanisms embodied in devices for measuring.elapsed periods orint'ervals of elapsed time.

'Elmers of. the type referred to are generally used to measure elapsedperiods of. time of varions lengths regardless. of whether the period isonly attraction of a minute or a substantial period of many minutes oreven hours of time. A numbe of pcpuiar'forms' of timers of this nature.now availablev have a maximum range of one hour slncethere is av greatdemand for timers of this mugs of time intervals. The present invention,however, is applicable to timers having even greater ranges than onehour.

In using ldmers of this nature for measuring relatively short. intervalsof time such as a fraction of one lllrimitc,v or even up to a fiveminute interval for example. it has been found that measurement of suchrelatively short intervals cannot be made as accurately as intervals ofconsielerabh! greater length. This is in part due to the fact thattolerances encountered in manufactnring timers are such that a highdegree of accuracy cannot usually be expected when measuring relativelysmall intervals of time except in regard. to timers of a very preciseand expensive nature.

It has been found that timers comprising a doclrwork mechanism driven bya source of power ch, as. a coiled. spring. when operating at a relahivehigh rate of speed, appreciably overcome inaccuracies caused bymanufacturing tolerances and are much more. accurate. than when theoperate at slower speeds. It is therefore an object of the presentinvention to improve the accuracy of interval timers for measurine ageneral. over-all range of intervals of time by providing a dual-rangetiming mechanismoperated by a power driven clockwork mechanism which isoperated at av fast rate of speed while measuring relatively smallintervals of time cadets slower rate of speed while measuring relativelylarger intervals of time.

object of the invention to include mefimjithin the timing mechanismwhich will shift the. speed control mechanism at a specific.predetermined pmition within the total time measuring range. of thetiming mechanism and setting means thereof.

It is a further object of the invention to effect such change in therate of speed of the timing b! embodying therein speed regulating meanscomprising an escape wheel and a pallet member movable into and out ofengagement with said escape wheel, the time train of the timingmechanism operating at a fast rate of speed when the escape wheel andpallet member are disengaged and at a slower rate of speed when theescape wheel and pallet member are in engagement with each other.

It is still another object of the invention to adapt these principles toa timing mechanism to cause the pallet member to disengage the escapewheel after a predetermined interval of time has been measured by thetiming mechanism and thereafter permit the time train to run free of anyimpedance or control by the pallet member, whereby the time train thenruns at a very rapid rate of speed and provides sufilcientpower for ashort interval of time to operate, for example. a manipulating memberfor performing an operation relative to an associated mechanism such asoperating a valve or a switch, moving a member, or the like.

Details of these objects and of the invention. as well as other objectsthereof, are set forth in the following specification and illustrated inthe drawings comprising a part thereof.

In the drawings:

Fig. 1 is a front vertical elevation of a dualrange interval timermechanism embodying the principles of the present invention.

Fig. 2 is a side elevation of Fig. 1.

Fig. 3 is a rear vertical elevation of the timing mechanism shown inFig. 1.

Fig. 4 is a sectional side elevation of the mech anism shown in Fig. 3.

Fig. 5 is similar to Fig. 3 but showing certain elements of themechanism in different operative positions.

Fig. 6 is a rear elevation of a somewhat modifled embodiment of intervaltimer mechanism adapted for functions additional to those for which themechanism shown in Fig. 5 is specifically intended.

Fig. 7 is a side elevation, partly in section. of a valve operated bythe timing mechanism shown mm. 6.

Fig. 8 is a fragmentary vertical elevation of still another embodimentof mechanism operable by an interval timer mechanism embodyin theprinciples of the present invention.

Referring to Fig. l, the interval timer mechanism illustrated thereincomprises a dial II and a setting knob l2 rotatably mounted relative tothe center of said dial, the dial comprising a pinralityofindicia Itandacirculararrangemantof produce an inaccurate measurement. measuringintervals of time between, for example, jfive minutes and 60 minutes,timing mechanism appliance.

graduations It. In order that more accurate measurement of shortintervals of time may be made, up to some selected arbitrary maximumcommensurate with the characteristics of the timer such for example asfive minutes, the indicia and graduations for measuring such shortintervals are spaced apart a greater distance than the graduations andindicia for measuring longer intervals of time between, for example,five and sixty minutes.

During the measurement of any selected short interval of time up to theexemplary limit of five minutes, the mechanism operates at a fast rateof speed to return the pointer I8 of the setting knob I2 from a selectedsetting to zero. the pointer reaches zero, mechanism is caused tooperate which will effect a signal such, for example, as the sounding ofbell 28. Due to the fast rate of speed of the timing mechanism duringthe measuring of short intervals, the operation of the mechanism will behighly accurate, and in view of the wide spacings. of the graduationsand indicia on the dial for measurin such short intervals, saidintervals may also be set accurately by the knob l2 to a high degree ofaccuracy.

that inaccuracies in the operation of a timing mechanism are mostperceptible and effective to Thus, for

of the type illustrated herein will operate with a reasonably highdegree of accuracy for measur- "il'lg such so-called longer intervals oftime, and

while measuring such longer intervals, the mechanism is operated at arelatively slow rate of speed. Accordingly, the indicia and graduationsfor indicating such longer intervals of time are spaced more closelytogether on the dial than those for measuring short intervals of time,less anism illustrated and described herein, the fast speed has beenarbitrarily selected so as to be five times faster than the slow speedof the mechanism. This diiference may, of course, be varied to suit anyspecific situation with which the timing mechanism may be used. Thegraduations and indicia on the dial ID from zero to five minutes andfrom five minutes to 60 minutes have been appropriately arranged inaccordance with said difference between the fast and slow speeds of themechanism.

The timing mechanism may be mounted on any suitable supporting devicesuch, for example, as a panel 22 of either a domestic or industrial Thedial I may be secured to one side of said panel and a mounting frame 24is secured to the other side thereof. A bell 28 preferably telescopeswithin the rear of the mounting frame 24 but the peripheries thereof arerelatively spaced so as not to interfere with the sounding of the bell.In this embodiment of the invention, the bell also serves as anenclosure forthe timing mechanism.

The mechanism 26 comprises a time train composed of a plurality ofintermeshin wheels and pinions supported by stafis pivotally mountedbetween and perpendicular to a pair of spaced frame plates 28 and 38.The time train is driven by simple power means such as a coil spring 32which is wound around a winding arbor 34. to

which the setting knob I2 is secured at one end. The other end of thewinding arbor has fixed thereto a cam or timing disc 36. Said end of thearbor also rotatably supports a second timing disc 38.

Pivotally supported at one end by the frame plate 30 is an irregularlyshaped lever 48 somewhat resembling a T. The end of one leg of the leveris pivoted to the frame plate 38 by shoulder stud 42. Fixed to the leverintermediate two of the ends thereof is an upstanding pin 44. Spring 46normally biases the lever in a direction to maintain the pin"4'4 againsteither the periphery of disc 38 or against the walls of notches 48 insaid discs 38 and 38 when said notches are aligned as shown in Fig. 3.This is the position the notches 48 and pin 44 occupy when the knob I2is set in zero position as indicated in Fig. 1.

The periphery of disc 38 extends slightly beyond that of disc 36, anddisc 38 is pivotally movable relative to disc 35 for a limited amountcontrolled by pin 58 which is fixed to disc 36 and extends through ashort arcuate slot 52 formed in disc 36. This exemplary type of timer isthat which, in measuring short intervals of time, requires the settingknob I2 to be moved past the desired interval of time to be measured, inclockwise direction as viewed in Fig. and then moved backward incounter-clockwise direction, until the exact setting for the pointer i8is reached. This manipulation is for purposes of providing a sharpdrop-oii for the pin 44 relative to .the discs 36 and 38 at the end of adesired elapsed period of time, as is described hereinafter.

To describe a setting operation of the herein illustrated dual-timingmechanism, assume that a setting of three minutes is to be made. Thepointer I8 is first moved past the indicium 3. Such movement is inclockwise direction as viewed in Fig. 1 but in counter-clockwisedirection as viewed in Fig. 8 since the latter is a rear view of Fig. 1.When the arbor 34 is first moved in counter-clockwise direction in Fig.3, the disc 38 which is fixed to said arbor will be movedcounter-clockwise and such movement will be relative to the disc 38until the pin 50 of disc 38 engages the left hand end of the slot 52shown in Fig. 3. The discs will then move together in counter-clockwisedirection. During such movement, the sloping uppermost edge of notch 48in disc 36 as shown in Fig. 3 will engage pin 44 and cam said pin tomove it to the left, the upper end of lever 48 also being moved to theleft. The upper end of lever 48 is provided with a rightangledprojection 54 Which'engages a clapper 58 by which a bell 20 is sounded.

After being moved out of the notches 48 of the discs, the pin 44 willride on the periphery of disc 38L When the pointer I8 is moved past theindicium 3 on the dial and then moved backward, counter-clockwise inFig. l, but clockwise in Fig. 3, to dispose the pointer [8 on thegraduation of indicium 3, such clockwise movement of disc 36 will takeplace while disc 38 remains stationary until the pin 50 is disposed inthe end of the slot 52 in which it is shown in Fig. 3. Continuedclockwise movement will move the discs simultaneously but by this time,the notch 48 of disc 38 will not be in exact registry with the notch 48of disc 36. The notch 48 of disc 38 is provided with a sharp radial edge58 which overlaps th notch 48 of disc 36 as shown in Fig. 5.

When a setting has been made with the knob l2 and it is released themainspring 32 of the mechanism will cause the knob l2 to be movedaccesses eeiiht'emicerwlse m Fig. i arid in Figs. 3 and 5, such movementBeing overned by the speed at whih the tiiiie Thus, when the pointer I8reaches zero, the pin ll of lever 48 will drop off of the corner of disc38 defind by the sharp radial edge" 58 and cause the upper end of thelever in ts be moved quickly toward the right to assume the positionthereof hcwn iriFig"; 3 and while so moving, strike the clapper 56 andimpinge the same against the bell to tc'erfect a signal by sounding thebell to.

s As has been stated above, when the timin mechanism is used to measureshort intervals of time, the mechanism travels at a fast rate of speed.Said rate of speed may, if needed, be controlled by any Suitableii'ififis' Such as a relatively lightweight itaidlng Iriinbf B8edmp'rislng a disc mounted on a staff 62 which is pivotally supported atits ends by bearings supported by frame plates 28 and 38. The disc orthe member 86 is proiiided with a flail of spaced pallet pins 64 whichengage the teeth of an escape wheel 66 which is driven bythe time train.The moment of inertia of the disc or member 68 may be varied in order tovary the speed at which the time train and, consequently, the timingmechanism operates. If thejjclisc or the member 68 is made so as to bequite light in weight, the rate of speed of the time train will be quiterapid, and in most interval timers of this nature, mo're rapid than therate at which the average clock or watch operates. This is due to thefrequency of oscillation oi the retarding member 80 being much higherthan that of the balance Wheel of the averase watch or cloek. v 4

AS has al stl been above, when the timing mechanism is used to measurerelatively long intervals of time, that is for example, in excess offive minutes, the timingmechanism operates at a slow rate of speed. Therate is made slow relative to the fast rate by moving into engage- 'mentwith the escape wheel 66 a suitable pallet member .68 which, in theexample shown herein, is disc like and is supported by a staff 16 whichis pivotally supported at one end by a bearing 12 fixed relativeto frameplate 28 andat the other end by a shiftable bearin H slidably mountedwithin a guide slot 16 formed in frame plate 30. It will thus be seenthat the stan may be tilted either toward or away from the toothedperi'phery of escape wheel 86 so as to permit the pallet'pi'ns 18 of thepallet member 68 to be moved so as 'toengage or not engage the teeth oithe escape wheel 86. The bearing M is normally biased by any suitablemeans such as a preferably light spring 88 in a direction to dispose thestaff 10 so that'the pallet pins I8 of pallet member 68 engage the teethof the escape 1 wheel 66.

While the mechanism is operating at fast speed to measure shortintervals of time, a cam arm 82, fixed to lever 60, engages the outerend of bearing ll in such a manner as to hold the same shifted to itsposition wherein the "pallet pins 18. do not engage the teeth of theescape Such movements: the bearing 18 is effected by the lever 48 beingmoved to the left as viewed in Figs. 3 and 5, carrying cam arm 82 of thelever therewith and causing the outer end of said arm to disengage thebearing 14 sufilciently to permit it to move toward the pivot of theescape wheel, the slot 16 which guides said bearing being radiallydisposed with respect to the axis of the stafi 84 of the escape wheel66.

The shifting of bearing 14 and the aforementioned movement of the leverto the left in Figs. 3 and 5 at the predetermined arbitrary position ofthe setting knob l2, selected in this exemplary timer at the five minuteindlcium, is affected by additional notches defined by shoulder 86 ondisc 36 and shoulder 88 on disc 38. The outer corner of shoulder 86 issomewhat rounded so that when said discs are moved counter-clockwise asviewed in Figs. 3 and 5 while effecting the setting of a long period oftime, in excess of five minutes, the rounded shoulder 86 of disc 36 willengage pin 44 ahead of shoulder 88 on disc 38. However, when the discsare moving clockwise in timing direction as distinguished from settingdirection, the sharp radial edge of shoulder 88 will trail roundedshoulder 86 and aiiord a sharp drop-off for pin 44 when the timing discand setting knob l2 reach during timing movement the predeterminedposition arbitrarily selected at the five minute interval on the dial.

Assuming that the timing mechanism is used to measure a so-called longinterval of time of twenty minutes, for example, the knob l2 will bemoved in setting; direction and will cause the discs 36 and 38 to bemoved counter-clockwise in setting direction as viewed in Figs. 3 and 5.During such movement, the pin 44 of lever 40 will be disposed on theoutermost periphery of disc 38 as shown in Fig. 5. When the discs aremoving clockwise in Fig. 5 during timing movement thereof, the lever 48will be held in the position shown in Fig. 5. In this position the camarm 82 will permit the pallet member 68 to engage the escape wheel 65.When the liveminute interval is reached, the pin 44 will drop on of theedge of the shoulder 88 of disc 38 and impart movement to the lever 48toward the right in 5, whereupon the cam arm 82 will engage theshiftable bearing 14 and move it away from the staff 84 of the escapewheel, against the influence of spring 89, to the osition of saidbearing shown in Fig. 3, thus disengaging the pallet member from theescape wheel. Such movement of lever 48. in this embodiment, will alsoactuate clapper 56 to sound the bell 28. The time train will thereafteroperate at its fast rate which is much morerapid than the slow rate ofspeed, causingt-he timing discs 36 and 38 to move more rapidly, as wellas the knob l2. 7

When the pointer 8 reaches the zero position, the shoulder defined bythe sharp radial edge of the shoulder 88 of the disc 38 will be disposedadjacent the pin 44 and permit the pin to drop off of the sharp cornerdefined by radial edge 58 of disc 38 into notches 48 of the timingdiscs, said notches then being substantially aligned. This will causethe lever 40 to again move to the right to its position shown in Fig. 3,due to the biasing influence of spring 46, and impinge the clapper 56against bell 20. For convenience. said bell may be suitably supported bybracket 90 which may be supported by any convenient part of themechanism such as frame plate 30. After the signal has been made by thebell. movement of the mechanism is stopped after a few seconds of timeby any suitable means, not shown, such as a finger fixed to arbor 34engaging a fixed stop secured, for example, to one of the frame plates28 or 30.

In the embodiment of the invention shown in Figs. 6 and '7, it iscontemplated that, either in addition to or without sounding a signalsuch as ringing the bell 20, mechanism of the type comprising thepresent invention may be utilized to perform other useful operationsrelative to associated mechanism. For example, there is illustrated inFig. 7 a valve 92 which is operable by an actuating member 94 movable,for example, in an axial direction. The mounting frame 24 of the timermay be fixed to the valve 92 as illustrated in Fig. 7 so as to disposethe timing mechanism so that it can actuate member 94.

Fixed to the outer timing disc 36 is any convenient operating means suchas a curved cam 96. The portion of the cam which is fixed to the timingdisc 36 is preferably fiat and parallel to the disc, and one end 98thereof extends away from the plane of the disc 36 as shown in Fig. 7.Thus, the timing mechanism may be arranged to operate so that when thesetting knob I2 reaches zero, for example, the cam 96 will be disposedadjacent the actuating member 94 as shown in Fig. 7. When this occurs,the L-shaped arm I00, which functions similarly to the lever 40 in theembodiment shown in Figs. 1 through 5, will be moved to the right asshown in 6 as a result of the pin I02 thereon dropping off of theshoulder 58 of cam 38.

It will be seen that the right hand end of arm I has a cam surface I04which functions similarly to the cam arm 82 of lever 40. Movement of camI04 relative to shiftable bearing M will disengage the pallet member 68from the escape wheel 66. In this embodiment of the invention,

it may be desirable to omit the retarding member 60 illustrated in theembodiment of Figs. 1 through 5. If the retarding member is omitted,disengagement of the pallet member 68 from the escape wheel 66 willpermit the mechanism to run entirely free from any retarding eifect, andsuch movement therefore will be at a Very rapid rate compared to that atwhich the mechanism operates when the pallet member engages the escapewheel. Such free running of the time train will cause the timing disc 36and end 98 othe cam 96 thereon to be moved very rapidly. The kineticenergy of the free rapid movement of the mechanism will provide arelatively great amount of force which will be imparted to the end 98 ofthe cam in order to effect movement of the actuating member 94 of thevalve toeither open or close the valve, depending upon the manner inwhich the member 94 functions. After the cam end 98 has movedsufficiently t. actuate the valve member 94, the timing mechanism may bestopped by an suitable means, not shown.

In Fig. 8, there is illustrated a still further example of mechanismwith which the principles of the timing mechanism comprising the presentinvention may be employed. InFig. 8, there is shown a lever I06 pivotedat I08 for example to the rear frame plate 30, of the timing mechanism,said lever having a pin Ill] which coacts with the timing discs and 38thereof. Lever I06 corresponds to levers I00 and 40 of the twoembodiments of the invention described hereinabove and the control ofthe movement of the lever I06 is similar to the control of movement oflevers 40 and [00.

When, for example, the zero setting of the timer is reached by thesetting knob on arbor 34 of the mechanismin Fig. 8, the pin IIO willdrop off of the radial edge 58 of disc 38 and cause the upper end II2 oflever I06 to be moved clockwise in order to shift the movable bearing 14in a direction to disengage the pallet member 68 from the escape wheel66. As in the embodiment shown in Figs. 6 and 7, the mechanism shown inFig. 8 preferably does not include the retarding member 60 in theembodiment as shown in Figs. 1 through 5. Thus when the pallet member 68is disengaged from the escape wheel of the mechanism shown in Fig. 8,the time train will then run free of any retarding effect of the palletmember and such movement will be at a very rapid rate to impart rapidmovement to the timing disc 36 while moving in counter-clockwisedirection as viewed in Fig. 8.

Fixed to the lower end II4 of the lever I06 is a projection II6 whichengages a movable switch member or blade H8. During the operation of thetiming mechanism while moving from a predetermined setting to zero, thelever I06 will maintain the switch contact of movable blade II8 of theswitch in engagement with the contact of fixed blade I20 thereof inorder to maintain the switch closed. However, when the zero setting isreached and the lever I06 is shifted clockwise to disengage the palletmember from the escape wheel, the lower end II4 will also cause theprojection II6 to move so as to effect a disengagement between theswitch contacts of blades H8 and I20 of the switch so as to break thecircuit of any mechanism appliance with which the timing mechanism maybe used, such as, for example, a toaster.

The particular exemplary illustration shown in Fig. 8 is a fragmentaryportion of a so-called pop-up type toaster wherein the depressing knobI22 may be moved from its starting position shown in dotted lines in theupper portion of the figure to the dotted line position thereof shown inthe lower portion of the figure in order to effect a setting of timeduring which the toaster is to operate. A stop comprising an adjustableeccentric I23 is provided if desired to control the limit of the initialsetting of the timing mechanism. Downward movement of the knob I22 willcause arm I24, fixed to disc 36 to be moved from its initial dotted lineposition shown in the upper part of Fig. 8 to the set position thereofshown in dotted lines in the lower part of Fig. 8. In the latterposition, the end of arm I24 engages the adjustable stop I23.

When the timer is moving in the timing direction, counter-clockwise asviewed in Fig. 8, the arm I24 will gradually move upward and slowlycarry knob I22 therewith until the pin I I0 of lever I06 drops off thecorner of disc 38 defined by radial edge 58. This corresponds to thezero setting of the timer and opens the switch contacts to break theheating circuit of the toaster. Such movement of the arm I06 will, asstated above, disengage the pallet member 68 from the escape wheel andwill thereafter permit the mechanism to run free from impedance by thepallet member and cause the timing disc 36 to move very rapidly incounter-clockwise direction, carrying the arm I24 thereof upward at arapid rate of speed. Arm I24 will also move the knob I22 upward in arapid manner. Assuming that the knob I22 is connected to the carincludedcertain details, it should be understood that the invention is not to belimited to the precise details herein illustrated and described sincethe same may be carried out in other ways, falling within the scope ofthe invention as claimed.

We claim as our invention:

1. A dual range timing device comprising in combination, a single timetrain, power means to drive said train in a single predetermineddirection, mechanism comprising an escape wheel and pallet memberassociated with said time train and operable to cause it to be driven atone rate of speed for a desired predetermined period of time, saidpallet member being movably mounted for movement into and. out ofengagement with the escape wheel, settable means movable in settingdirection to determine said period of time, said settable means beingdriven oppositely in timing direction by said time train, and meansactuated by the settable means and engageable with the pallet memberwhen said settable means reaches a specific position during its movementin timing direction to cause said pallet member to be moved fromengagement with said escape wheel, whereby said time train operatesthereafter at a faster rate of speed during continued movement of saidsettable means in timin direction.

2. A dual range interval timer comprising in combination, a single timetrain, power means to drive said train in a single predetermineddirection, means settable to determine the total period of time duringwhich the time train shall operate, speed regulating mechanismassociated with said time train and operable to cause it to be driven ata fast rate of speed during a first range of settings to measure aselected relatively short interval of time, a second speed regulatingmechanism movable into engagement with the time train to cause the timetrain to be driven at a slower rate of speed, and means automaticallyoperable when a predetermined position in the range of movement of thesettable means is reached to engage said second speed regulatingmechanism with the time train to cause said time train to be driven at aslower rate of speed during a second range of settings while measuring aselected interval of time in excess of the maximum of said shortintervals.

3. A dual range interval timer comprising in combination, a single timetrain, power means to drive said train in a single predetermined.direction, means settable to determine the total period of time duringwhich the time train shall operate, speed regulating mechanismassociated with said time train and. operable to cause it to be drivenat a fast rate of speed during a first range of settings to measure aselected relatively short interval of time, a second speed regulatingmechanism normally engaging with the time train to cause it to be drivenat a slower rate of speed, a timing disc driven by said time train, anda lever controlled by said disc and movable automatically when apredetermined position in the range of movement of the settable meansand timing disc is reached to disengage said "second speedregulatingmechanism and cause said time train to be driven at a slowerrate of speed during a second range of settings while measuring aselected interval .of time in excess of the maximum of said shortintervals.

4. A dual range interval timer comprising in combination, a single timetrain, power means to drive said train in a single predetermineddirection, means settable to determine the total period of time duringwhich the time train shall operate, an escape wheel associated with thetime train, a first pallet member continuously engaging the escape wheelto cause the time train to be driven at a fast rate of speed during afirst range of settings to measure a selected relatively short intervalof time, a second pallet member movable into engagement with the escapewheel to cause the time train to be driven at a slower rate of speed andmeans automatically operable when a predetermined position in the rangeof movement of the settable means is reached to engage said secondpallet member with said escape wheel and cause said time train to bedriven at a slower rate of speed during a second range of settings whilemeasuring a selected interval of time in excess of the maximum of saidshort intervals.

5. A dual range interval timer comprising in combination, a time train,power means to drive said train, means settable to determine the totalperiod of time during which the time train shall operate, speedregulating mechanism comprising an escape wheel and pallet memberassociated with said time train, a timing disc driven by said time trainand a lever controlled by said disc and operable to maintain the palletmember disengaged from the escape wheel and cause the time 1? train tobe driven at a fast rate of speed during a first range of settings tomeasure a selected relatively short interval of time, said disc andlever being automatically operable when a predetermined position in therange of movement of the settable means and disc is reached to engagesaid pallet member with said escape wheel and cause said time train tobe driven at a slower rate of speed during a second range of settingswhile measuring a selected interval of time in excess of the maximum ofsaid short intervals.

6. A dual range interval timer comprising in combination, a time train,power means to drive said train, means settable to determine the totalperiod of time during which the time train shall operate, speedregulating mechanism comprising an escape wheel and a first palletmember associated with said time train and operable to maintain thepallet member disengaged from the escape wheel and cause the time trainto be driven at a fast rate of speed during a first range of settings tomeasure a selected relatively short interval of time, a second palletmember normally engaging said escape wheel to control the speed of saidtrain while running at said fast rate, and means automatically operablewhen a predetermined position in the range of movement of the settablemeans is reached to engage said first pallet member with said escapewheel and cause said time train to be driven at a slower rate of speedduring a second range of settings while measuring a selected interval oftime in excess of the maximum of said short intervals.

'7. A dual range timing device comprising in combination, a time train,power means to drive said train, mechanism comprising an escape wheeland pallet member associated with said time train and operable to causeit to be driven at a predetermined rate of speed for a desired period oftime, said pallet member being mounted for movement intoand out ofengagement with said escape Wheel, vsettable means operable to determinesaid period of time, and means operated by said time train andengageable with the pallet member when said period has elapsed todisengage said pallet member from the escape wheel to permit said timetrain to operate thereafter free from the retarding efiect of saidescapement and at a greatly increased rate of speed.

MERRITT VAN VALKENBURGH.

LAWRENCE J. LAVIANA.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

